Electronic discharge device for ultra high frequency energy generation



J. W. WEST ELECTRONIC DISCHARGE DEVICE July 8, 1947.

. 7 FOR ULTRA HIGH FREQUENCY ENERGY. GENERATION Filed Jan. 7, 1944 2Sheets-Sheet 1 6 4 2 8 2 8. 1.1 4 2 6 2 d. 3 on 2 O 2 2 0 3...... WW 6 3f vua 2 3 7 3 2 2 .3 5 2. .J 2 6 4 l 4 2 4 a 3 0 4 5 3 2 M9 4 v 4 44FIG. 3

- INVENTOR J m WEST A TORNEY July 8, 1947. w WEST ELECTRONIC DISCHARGEDEVICE FOR ULTRA HIGH FREQUENCY ENERGY GENERATION Filed Jan. 7, 1944 2Sheets-Sheet 2 FIG. 7

F IG. 8

INVENTOR J. M. WEST BY 4 ATTORNEY Patented July 8, 1947 giant ELECTRONICDISCHARGE DEVICE FOR ULTRA HIGH FREQUENCY ENERGY GEN- ERATION John WV.West, Jackson Heights, N. Y., assignor to Bell Telephone Laboratories,Incorporated, New York, N. Y., a corporation of New York ApplicationJanuary 7, 1944, Serial No. 517,382

18 Claims.

This invention relates to high power electronic discharge devices andmore particularly to such devices employed in generating ultra-highfrequency energy radiations.

The primary object of this invention is to insure stable dynamic andelectrostatic characteristics in the operation of the device wherebyhigh output efiiciency is maintained constant over long service periods.

Another object of the invention is to facilitate the mechanical assemblyof the device to obtain coaxial symmetry of the internal electrodes withthe enclosing electrodes.

A further object of the invention is to protect the hermetic sealsextending from the exterior of the device so that accidental impact willnot injuriously affect the highly evacuated discharge path in thedevice.

Another object of the invention is to efiectively minimize theelectrostatic impedance between the high and low potential electrodes inthe device.

A further object of the invention is to depreciate the effect of theintense heat energy generated in the device from varying theelectrostatic properties of the respective electrodes.

Still another object of the invention is to willciently insulate therespective electrodes in the device at the nodal point of high frequencyvoltages supplied to the device whereby energy strains are least apt tooccur during operation.

A further object of the invention is to obtain uniform balance in thedisposition of the insulating spacers between the electrodes so thatsubstantially no interference is encountered with the current supplyconductors extending to the various cooperating electrodes.

In accordance with this invention these objects and other advantages areattained in a high power duplex or push-pull electronic oscillationgenerating device having a metallic casing, each end of which forms anexternal anode element which may be cooled to dissipate heat energygenerated during operation and the casing forming a completely evacuatedand sealed receptacle enclosing and shielding the cooperating electrodesfor generating the power utilized in the operation of the device. A dualcontrol electrode assembly is mounted within the casin in symmetricalrelation to the anode elements of the device and cooperates therewith toform capacitive and inductive resonance chambers or cavities forcoupling these electrodes in an oscillatory circuit. A dual cathodeassembly is mounted within the control electrodes or grid assembly andis coaxially related thereto along the Whole length of the device toproduce the high electron source for each unit and introduce distributedcapacity and inductance components in the communicating paths to thecontrol electrodes. This construction facilitates the introduction ofthe supply conductors to the cathode and control electrode assemblies ata medial plane of the device where the high frequency voltages arenegligible so that energy strains do not occur in the seals of theconductors.

A feature of this construction relates to the symmetrical interspacialrelation of the internal electrode assemblies with respect to the duplexanode elements of the device to insur uniform electrical characteristicsduring operation for a relatively long service life. This isaccomplished by mounting the electrodes in coaxial relation andmaintaining them in constant symmetry by a plurality of radial spacermembers of h gh dielectric strength and sufficient surface resistance towithstand the potential gradients between the electrodes. These spacermembers are mounted in a medial plane of the device between the casinsand dual grid assembly and between the dual grid assembly and the dualcathode assembly, the spacers between the outer adjacent electrodesbeing uniformly distributed in transverse relation and the spacersbetween the inner adjacent electrodes being distributed in similarfashion but oriented uniformly in relation thereto. This arrangementfacilitates the coupling of the various groups of electrodes to theirrespective leadin conductors to provide symmetrical grouping of theconductors to appropriate sealed terminals mounted on the casing andalso contributes to the rigid mounting of the coaxial electrodes withoutdanger of torsional stress therein.

Another feature of this construction relates to the fabrication of thespacer members to the walls of the cylindrical electrodes in the device.This is accomplished by providing a coherent metallic coating on eachend of the insulating spacers and seating the metal coated ends insockets on the surfaces of the electrode supports.

A further feature of the invention relates to the mounting of theinsulating spacers in relation to the coaxial electrode units wherebyexpansion forces are compensated to prevent change in symmetricalrelation between the respective electrodes in each unit. This isaccomplished by mounting one end of each insulating spacer rigidly in acommon support element for each group of spacers and affixing the otherend of the spacer in a yieldable socket or spring mounting attached tothe respective support column of the groups so that circumferentialexpansion of the coaxial support columns does not materially affect thenormal space relation between the electrodes. This construction,furthermore, facilitates the assembly of the dual grids cathodes withinthe casing since the spacers are rigidly aimed at one point to thecolumns each column with the radial spacers may be inserted in positionand when properly aligned the yieldable sockets may be afiixed to theadjacent walls of the grid column and respectively.

Another feature of the invention is concerned with the distribution ofthe spacer members between the electrode assemblies and the currentconductors extending through the wall of the receptacle to the variouselectrodes whereby both the spacers and the conductors are situated inthe nodal plane of the device to reduce high frequency current strainsin the insulators and hermetic seals of the conductors. This isaccomplished by mounting the cathode assembly from the inner surface ofthe grid assembly by oppositely disposed spacer members and in thetransverse direction in the same plane supporting the cathode assemblyby a radial conductor sealed through the wall of the casing and anotherinsulating spacer in directly opposed relation to the conductorconnecting the oathode and grid assemblies together. A pair of radialconductors are also disposed on opposite sides of the first conductorand are connected to the cathodes and grids. respectively, to groupthese low potential conductors together. The grid assembly, togetherwith the enclosed cathode assembly, is mounted coaxially within theanode casing by equally spaced insulating members in transverse relationwith two of the members disposed radially adjacent the low potentialconductors and the others in opposed relation so that the outer spacersare or'ente- 45 degrees with respect to the inner spacers and thecentral radial conductor. The high potential conductor for the anode issealed in the anode wall intermediate the last-mentioned outer spacermembers and directly opposite the posi-- tion of the low potentialconductors so that high leakage resistance is attained between theseconductors. An auxiliary advantage of this arrangement is the provisionof adequate protective housings for the insulated conductor sealsextending from the device. The group of low potential conductor seals isenclosed in an insulating receptacle rigidly secured to the anode casingand suitable terminals carried thereby are provided to accommodate thecurrent supply lines to the conductors of the device. The anodeconductor seal is protected by a cylindrical sleeve which, togetherwith. the insulated conductor, forms a concentric line for derivingpower from the dual output electrodes or anodes of the device.

A further feature or the invention relates to the inter-electrodeshielding to increase capacitive coupling between the high potentialanode and thecathode assembly and sustain oscillating current fields inthe device more readily. This is accomplished by mounting annularelectrostatic shields on the cathode assembly, the shields extendingoutwardly beyond the inner wall surfaces at the ends of the anodeportions and being provided with a series of openings to permit thepassage therethrough of the lateral wires of the grids. These shieldsare reinforced by suitable surface configurations to eliminate warpingso that the intense heat energy generated d manufacture of the devicewill not affect their spacial relation with respect to the cooperatingelectrodes in the de vice.

These and other features and advantages of the invention will moreclearly understood from e following detailed description when consideredwith the accompanying drawings:

Fig. 1 is a view in elevation of a high power, high frequency push-pullelectronic oscillator device with portions of the container and internalelectrodes broken away to show the detailed construction;

Fig. 2 illustrates the device in cross-section on the line 22 of Fig. 1;

Fig. 3 is a partial view in cross-section on an enlarged scale taken onthe line S-3 of Fig. 2 to illustrate the detailed assembly of the radialspacer members between the electrodes;

Fig. l is an enlarged perspective view of the components of theinsulating spacer members in exploded fashion to illustrate one of thefeatures of this invention;

Fig. 5 is a partial perspective view of the grid and cathode assembliesin one end of the device with the electrostatic shield of this inventionmounted in relation to these electrodes;

Fig. 6 is an enlarged cross-sectional view of the mounting assembly ofthe grids and cathodes within the device as shown in Fig. 2 illustratingin more detail the spacing of the sup-porting columns of theseelectrodes;

Fig. 7 is a plan view of the inter-electrode shield of this invention;and

Fig. 8 is a cross-sectional view of the shield taken on the line 88 ofFig. 7.

Referring to the drawings and particularly to Figs. 1, 2 and 3, theembodiment of the oscillation generator of this invention, as showntherein, comprises a completely enclosed metallic casing which forms ahighly evacuated container or vessel for the dual or duplex units whichconstitute the reciprocal oscillation generator elements for producingultra-high frequency energy in microwave band transmission systems. Thecasing is formed of an intermediate cylindrical shell or column 2a ofcopper, which is hermetically joined or soldered to a pair ofterminating solid metallic masses 2! and 22, preferably of copper,having a central passageway therethrough of substantial area but of lessdiameter than the diameter of the intermediate shell 26. The masses 2!and 22 constitute external anode portions of the device and may beprovided with circumferential radial fins 23 for readily dissipating theheat energy generated in the copper masses of the anodes duringoperation of the device. The cooling fins may be replaced by any othertype of cooling instrumentality, such as a Water circulating jacket or acoil of pipe surrounding the anode mass, the fins being shown as oneexample of cooling means. The shell and anode portions enclose dual orduplex electrode assemblies mounted in cooperating relation to the shelland anode portions so that the device functions as a push-pull triodeoscillation generator in which the current flows reciprocally inopposite phases between the two triodes to generate high power atultra-high frequencies in the range from 0 to 1500 megacycles, with apower output of 1 kilowatt to l'megawatt depending on the dimensions andconstants of the electrodes and resonant cavities of the device. Inorder to proportion the capacities between the electrodes in each triodeand also to reduce the transit time of the electron flow to a minimum,the cooperating electrodes within each anode portion are mountedcoaxially and relatively close to the internal surface of the massdefined by the central opening therein. Each anode portion is alsoprovided with a large diameter opening 25 on the outer end thereof whichcommunicates with the central cavity in which the electrodes arelocated.

The cooperating electrode assemblies are oppositely disposed box-likecylindrical cathodes 25 and 26 and oppositely disposed cylindricalopenwork control electrodes or grids 2'! and 28 coaxially positioned inthe openings of the anode portions 2| and 22, respectively. The cathodeshave a large cylindrical surface uniformly spaced in close relation tothe internal s rfaces of the anode portions and this surface is coatedwith an electron emissive material, such as barium and strontium oxide,to supply a copious emission of electrons across the short gap to theanode in order to convey a large current necessary to generate the highpower to be delivered by the device. The duplex cathodes areelectrically connected together in opposed relation by an innerconductor column or tubular member 29 of small diameter and the duplexgrids are electrically connected together by an intermediate column ortubular member 3i! of larger diameter, both columns being in concentricrelation to the outer column 23 of the device. A central metallicstandard or support rod 3i extends through both cathodes and the column29, the rod being insulated from the cathode enclosures by insulatingbushings 32 at each end of the enclosures. Each cathode is heated toemission temperature by an internal heater element 33, of tungsten,which may be in the form of a large diameter helix surrounding the rod3| and attached at one end to the rod and at the other end to theterminating end of the cathode supporting column 29. The cathode is alsoprovided with disc shields 34 at opposite ends of the enclosures toserve as heat deflectors for confining the heat energy of the cathode tothe cylindrical surface opposed to the anode surface. Each control gridis formed of an end disc 35 having a flanged periphery which extendsacross the large diameter opening 2% in the anode casing and forms apartial electrostatic shield between the cathode and the anode. Aplurality of parallel wires extend between the grid disc 35 and theintermediate column 36 and are interposed between the active cathodesurface and the internal surface of the anode portion.

The opposite end of the cathode enclosure, that is, the end directedtowards the center of the casing is also electrostatically shielded withrespect to the anode, to increase the capacitive coupling between theseelectrodes of large difference of potential. In accordance with thisinvention this shielding efiect is accomplished by a metallic discmember 36, shown more clearly in Figs. 5, 7 and 8. This disc shield isprovided with a central flange ring 3! which is afiixed to the end ofthe inner column 29 adjacent to the cathode heat shield 35 and is alsoprovided with a plurality of arcuate slots 38, to permit groups ofupright wires of the grids to pass freely therethrough. The disc isprovided with a plurality of continuous corrugations 39 intermediate thering 31 and the slots 38, the ribs between adjacent slots are reenforcedby a discontinuous corrugation 46 and the peripheral edge of the disc isprovided with a flange M, the corrugations and flanges contributing tothe strength of the thin disc to prevent distortion thereof due to thehigh temperatures encountered during manufacture and operation of thedevice.

As shown in Fig. 1, the device may be provided at either end with afrequency adjusting terminating element, to regulate the capacitivecoupling within the active electrode areas between the controlelectrodes and the anodes. The adjustable element comprises a metalliccap d2 brazed to the end of the anode to form a closure for the largediameter cavity 24 in the outer end thereof, the cap being provided witha central bushing :13 which extends into the cavity. The bushing isinternally threaded to receive a screw member 44 having an externalknurled knob 45 extending beyond the cap 12 and affixed at the other endto a metallic condenser plate or disc it which is secured to the screwmember by a retainer ring 41.. A metallic Sylphon bellows member 48surrounds the bushing and screw member and is attached at opposite endsto the retainer ring 41 and the inner surface of the cap 42 to preventleakage of air into the casing through the threaded connection. Externalto the bushing the screw member M is enclosed by a short bellows sleeve49 carried by the knob and joined to the cap by a tight-fitting flangedring at. The condenser disc 45 is variably movable in reciprocablerelation by the screw and knob member to change the capacitive couplingbetween the anode and the grid in the large area cavity of the anode andthereby accurately tunes the anode-grid circuit to the desiredfrequency.

Because of the mass of the cooperating electrode assemblies, i. e., thedual cathodes and grids together with the coupling support columns asand 359, respectively, disposed within the dual anode casing and therequirement of limiting the insulation supports of these assemblies tothe nodal point where the high frequency potential difierence issubstantially zero so that energy stresses are substantially eliminatedon the insulating supports and the fragile seals of the currentconductors entering the device, there arises considerable difficulty,from a mechanical and electrical point of View, concerning adequatefacilities for maintaining constant spacial relation between therespective electrodes in the dual units since it is essential that theuniformity in spacing between the cathode grid and anode in one unitmust be the same in the other unit to insure balanced reciprocal outputpower to obtain high efiiciency operation in ultra-high frequencytransmission systems. Furthermore, the limitation of the location of theinsulating supports requires that these supports must provide highdielectric impedance to insure positive resistance to high frequencyenergy fields between the elec trodes of large potential difference andthe supports must be relatively strong to rigidly hold the individualdual electrodes in uniform coaxial relation with respect to the anodesof the device. In mounting stand-off insulators or spacer rods betweenthe concentric columns at the nodal point of the device it is desirableto avoid connections which project through the columns since suchprojections alter the inductive characteristics of the respectivecavities and may form localized points which develop arcing paths in thedischarge space. Furthermore, it is difficult to fasten the insulatorswithin the columns by metallic attachments without considerably reducingthe limited insulation path across the gap between adjacent columns.

However, in accordance with this invention, these difiiculties areovercome and a substantially rigidsupporting structure is provided tosecure constant coaxial relation between the electrodes in the units andconstant maintenance of the appropriate values of capacity andinductance of the cavities coupling the triode units in the oscillatorcircuit. This is accomplished .by mounting a plurality of cylindricalstand-oh" insulators or insulating spacer rods in spaced relation in aradial direction between the inner and intermediate columns 29 and 3.9and also between the intermediate column Sil and the outer column orintermediate casing portion 2.6, the spacer rods in the outer cavitybeing staggered with respect to the spacer rods extendin across theinner conductors between the cathodes and grids. These rods are locatedin a single plane at the nodal or medial point of the device, as shownin Figs. 1 and 3, and constitute a reenforced support assembly formounting the cathode and grid assemblies in positive coaxial relationwithin the anode cavities so that electrical stresses are held to aminimum in the discharge path of the device. The detail construction andthe fabrication of the spacer rods with respect to the coaxial columnsis shown clearly in Figs. 2 to 4, inclusive, and Fig. 6 and reference tothese figures will show the various advantages attained by theconstructional assembly involved in this invention.

As shown in Fig. i, the stand-ofi insulator or spacer rod comprises ahighly refractory material such as Lavite or Steatite which has itscylindrical surface undercut at uniformly spaced intervals to providealternate diameters of two cu'mensions and thereby materially increasethe over-all length of the insulation resistance between the en-ds ofthe rod. The small diameter ends of the rod are coated with a stablemetallic covering, such as steel, by the spray method using a Schoopspistol, in order to retain a film of soldering metal thereon and preventthe separation of the solder film from the ends of the insulator duringthe fabrication process of the spacer members in the device. The innercolumn 29 which supports the dual cathodes is mounted coaxially withinthe intermediate column 39 by providing a metallic block 53, shown inFig. 6, which is sweated to the column at a central point, the blockbeing provided with spaced apertures on three sides to form sockets forthe insulating spacers and an elongated opening 5% extending opposite toone of the socket openings. A pair of diametri ally opposite spacer rods5i are positioned in the sockets in the block and a similar spacer rodis mounted in the remaining socket at right angles to the pair of rodsaligned across one diameter of the space between concentric columns 2%and 3E). The metallic coated ends of the spacer rods 55 extending intothe block are provided with a film of high melting-point solder, such as80 per cent copper and 20 per cent silver, and the insulator rods arerigidly sweated into the sockets to for-ma tight joint therein. Theunderco-at of steel On. the ends of the insulator 5i is securely bondedto the refractory ,material or the spacer rod and is not affected by theheat treatment required to form the brazed or sweated joint in .thesockets of the block 53. Therefore, no difiiculty is experienced informing a substantially rigid joint in the block due to the specialpretreatment of the ends of the insulators prior to the solderingoperation. The outer metalcoated ends of the spacer rods adjacent theinner surface of the grid support column 38 are sweated, by highmelting-point solder, to a short cylindrisleeve 55 in a resilient saddleplate or socket member 55, formed of spring steel, shown in Fig. 4, thesaddle or socket having return bend portions 5? which terminate to therear of the sleeve as outwardly bent feet 53, which are securelysoldered to the inner wall of the grid column 35, to anchor the saddlein directly opposed relation to the socket openings in the block 53.These saddles or sockets are sufficiently rigid to maintain the cathodecolumn 2! in coaxial relation to the grid column to and the respectivecathodes 25 in relation to the respective grids 23 in the oppositelydisposed units. However, due to expansion contraction of the cathodecolumn 29 and block 53, under operating temperature conditions, thesaddles are slightly yieldable to compensate for the expansion of thecolumn and block so that distortion and stresses do not occur in theassembly.

The grid supporting column 36 is provided with a plurality of circularopenings 59 at equally spaced points in line with the resilient saddles5% on the inner surface thereof, two of the openings be ng intermediatethe three inner spacing insulator rods and the other two openings beingdiametrically opposite the above-mentioned openings and are equallydistributed around the per phery of the column, a line passing througheach pair of opposed apertures, being at i5 degrees, with respect to thediametrical line running through the inner stand-on insulators. Inaddition, the grid column Elli is provided with elongated narrow slots5&3 on opposite sides of each circular opening to permit slight yieldingor breathing of the column under high temperature conditions so thatpermanent distortion of the column or fracture of the joint between thecol and the outer stand-off insulators does not occur during operating.The inner ends of the larger size stand-oil insulators 55 between thegrid column and the anode column 253 are soldered into the circularopening to rigidly support the stand-on insulators with respect to thegrid column whereby the larger size spacer rods are staggered inrelation to the smaller size rods within the grid column. The free endsof the outer rods 5! are seated and soldered into sleeves ti of socketsor saddle members 62 of cut or pliable metal, such as steel, and thesesa dles are provided with tangle end portions 63 w h are sweated to theinner surface of the anode column as by high rnelting-point solder, torigidly support the combined electrode supporting columns within thedevice longitudinally yet permit expansion of the columns withoutcausing deformation of the columns or breakage the insulators due to theresiliency of the sad- .les attaching the stand-oi? insulators to theinner surface of the anode column 2* The stagarrangement of the radialstand-oft insulatcrs between the coaxial columns of the dual electrodeunits materially enhances the supporting assembly of the internalelectrode structures with respect to the anode casing of the device andfacilitates the assembly of the structures since the dual cathodestructure may be mounted within the grid supporting column 39 prior tothe mounting of the grids on the column and the coaxial cathode and gridcolumns may be mounted within the outer anode column as prior toafiixing the anodes to the ends of the outer column. Furthermore, theuniformly distributed cross-bracing of the stand-off insulators andtheir location at the medial point of the structure strengthens thesupport of the dual electrode assemblies and minimizes high frequencyvoltage stresses on the insulator supports. Another advantage of thisconstruction is the fabrication of the distributed stand-off insulatorsto their respective supporting columns prior to insertion in thesurrounding column so that the peripheral soldering operation is allthat is necessary after insertion of the unit in the surrounding column.This insures axial symmetry between the coaxial columns and uniformspace relation between the cathodes and grids with respect to the anodeswhich surround them.

The uniform relation of the stand-off insula tors and the staggereddisposition of the outer radial rods with respect to the inner rodfacilitates the grouping of the low potential leading-in conductors tothe internal electrodes at one point on the circumference of the deviceintermediate two of the outer stand-01f insulator rods and thedisposition of the high potential leading in conductor for the anode ata diametrically opposite point of the device intermediate the remainingouter spacer rods. Therefore, the group conductors and the solitary highpotential conductor together with their fragile hermetic seals may beadequately protected against shock or damage from external sources. Asshown in Fig. 2, the intermediate casing column 20 is provided withthree drilled and threaded openings at a medial point intermediate thetwo lower outer stand-on. insulators and threaded metallic nipples E4, 65 and 56 are rigidly fastened to the column in circumferential seriesrelation with the nipple 64 in diametrical relation to theperpendicularly mounted stand-off insulator 5i between columns 29 and 30and centrally disposed with respect to the companion nipples 55 and 66,respectively. Each nipple is provided with a tapered knife edge sleeve6'! at the outer end and a vitreous tubulation 68 is hermetically sealedto the knife edge extension to form a tight joint with the nipple. Acentral conductor 69 extends through the cen tral tubulation and nipple64 and is connected within the column 25 to a flexible metallic strap Hiwhich in turn is connected to a rigid extension. H which passes throughan opening in the column 30 and an insulating bushing 12 located in anopening of the column 29. The extension H is securely attached to asocket sleeve '83 fastened to the central standard 3! within the column29 and a larger bushing 14 in the opening 54 of the block 53 holds thebushing 13 in position. A conductor 15 is sealed in the other tubulationand extends through nipple B5 and is connected to a similar flexiblestrap l'il, which is coupled to an extension 16 also extending throughthe grid column 3t and is afiixed to an abutment TI on the lower end ofblock 53. The conductors 69 and i5 supply current to the standard andcathodes whereby the helical heater elements 83 within the cathodes 25are heated to the proper temperature for heating the cathodes byradiation. A remaining conductor 13 extends through nipple 55 and thecorresponding tubulation at tached thereto and is attached within thecasing to a flexible strap it! which is joined to a short stub wire l9directly attached to the intermediate column 3?] for applying a suitablecontrolling potential to the dual grids supported by this column. Alarger diameter nipple S0; is threaded into an opening at the top of thecasing, as shown in Fig. 2, and carries a bell-shaped vitreous tube 8!,sealed to the tapered knife edge extension 82 of the nipple. A hollowcopper cup terminal 83 is sealed to the outer end of the tube 5! and aconductor 84 projects inwardly through the seal from the cup and iscoupled to a loop 85 within the casing, the other end of the loop beingjoined to the inner surface of the nipple 8b, to form an outputabsorbing element for deriving power from the cavity within the device.The entire casing is evacuated through an exhaust nipple 86 threadedinto the side of the casing, the nipple being sealed to a glasstermination 8'! which is sealed off after a high degree of vacuum isattained in the casing. The various nipples threaded into the peripheryof the outer column 26 in the medial plane thereof are hermeticallysealed to the column by a solder having a lower melting-point than thesolder employed in joining the stand-off insulators to the columns andthe saddles, the solder having a composition of lead 50 per cent andsilver 59 per cent. This lower melting-point solder is employed so thatthe soldered joints within the casing between the saddle supports andthe columns will not be affected by the subsequent soldering operationperformed on the sealing nipples.

The group of low potential conductors at the lower end of the casing, asshown in Fig. 2, are protected from injury by providing a metallic frameboss 88 which is shaped to conform to the configuration of the outercolumn 28 and is attached to the anode portions of the casing by screws.An insulating housing 39, such as ceramic or plastic, surrounds thegroup of conductor seals and abuts against the boss 88 and is attachedthereto by screws. The bottom of the housing is provided with aperturesto receive metallic ferrules or jack terminals 99 which carr attachinglugs SE to which extensions 92 are attached within the housing, theextensions, being coupled to the respective conductors extending fromthe seals. This structure forms an adequate protective housing for thegroup of sealed conductors extending from the vessel and provides meansfor coupling suitable plug conductors in the ferrules for applyingexternal voltages to the various electrodes. A cylindrical metallicsleeve 93 is threaded to the large diameter nipple Sil and forms aprotective housing for the anode lead-in conductor to protect thehermetic vitreous seal thereof. This metallic covering also facilitatesthe coupling of a coaxial line to the output of the device. The vacuumsealing tip 8? is also protected by a metallic cap M which encloses thetip and is threaded to the nipple 85 joined to the vessel.

While the invention has been disclosed with respect to a particularembodiment of the invention, it is, of course, understood that variousmodifications may be made therein without departing from the scope ofthe invention as defined in the appended claims.

W hat is claimed is:

1. An electronic discharge device comprising a pair of oppositelydisposed metallic anode portions having central cavities, a pair ofoppositely disposed cathodes mounted within said anode portions, coaxialmetallic hollow columns intermediate and joining said anode portions andcathodes respectively, radial insulating spacer members disposed betweensaid columns in a medial plane thereof, and means on at least one ofsaid columns forming interlocking seats supporting said spacer memberswith respect to said columns and being adapted to compensate forexpansion and contraction forces imposed on said spacer members.

2. An electronic discharge device comprising a pair of oppositelydisposed metallic anode portions having central cavities, a pair ofoppositely disposed cathodes mounted within said anode portions, coaxialmetallic hollow columns intermediate and joining said anode portions andcathodes respectively, radial insulating spacer members disposed betweensaid columns in a medial plane, and yieldable metallic members on atleast one of said columns forming interlocking seats supporting saidspacer members with respect to said columns and being adapted tocompensatc for expansion and contraction forces imposed on said spacermembers.

3. An electronic discharge device comprising a pair of oppositelydisposed metallic anode portions having central cavities, a pair ofoppositely disposed cathodes mounted within said anode portions, coaxialmetallic hollow columns intermediate and joining said anode portions andcathodes respectively, radial insulating spacer members having metallicterminations disposed between said columns in a medial plane, andmetallic sockets on at least one of said columns engaging said metallicterminations and forming interlocking seats supporting said spacermembers with respect to said columns.

l. An electronic discharge device comprising a pair of oppositelydisposed metallic anode por tions, a pair of oppositely disposedcylindrical control electrodes mounted within said anode portions, apair of oppositely disposed cylindrical cathodes mounted within saidcontrol electrodes, coaxial metallic columns interconnecting electrodesof each pair, a plurality of radial insulating spacer members extendingbetween said 001- i umns in a medial plane thereof, and resilientmetallic sockets on at least one end of said members and aflixed to theadjacent surface of said columns.

5. An electronic discharge device comprising a pair of oppositelydisposed metallic anode portions having central cavities, a pair ofoppositely disposed cylindrical control electrodes mounted Within saidcavities, a pair of oppositely disposed cylindrical cathodes mountedwithin said control electrodes, concentric conducting tubular membersjoining the respective pairs of electrodes, cylindrical steppedinsulator rods mounted in radial relation between said tubular membersin a medial plane thereof, said rods having metallic sleeveterminations, and resilient metallic sockets securing said rods to theinner surfaces of the tubular members joining said control electrodesand anode portions, respectively.

6. An electronic push-pull oscillating device comprising dual anodeportions coupled in op posed relation by an outer conducting sleeveportion and forming an enclosing casing, dual cylindrical grids disposedwithin said anode portions and coupled in opposed relation by anintermediate sleeve portion, dual cathodes within said grids and coupledin opposed relation by an inner sleeve portion, said sleeve portionsbeing coextensive and concentric with respect to each other, a pluralityof stand-off insulating rods extending radially between said sleeveportions in a medial plane, said inner and intermediate sleeve portionshaving recesses in spaced relation to accommodate the inner ends of therespective rods extending therefrom, and resilient socket members on theouter ends of said rods secured to the inner Walls of said intermediateand outer sleeve portions, respectively.

7. An electronic push-pull oscillating device comprising dual anodeportions coupled in opposed relation by an outer conducting sleeveportion and forming an enclosing casing, dual cylindrical grids disposedwithin said anode portions and coupled in opposed relation by anintermediate sleeve portion having spaced recesses therein andlongitudinal slots between said recesses, dual cathodes within saidgrids and coupled in opposed relation by an inner sleeve portion, saidsleeve portions being concentric with respect to each other, a recessedblock mounted on said inner sleeve portion, a set of stand-oil"insulating rods extending radially from said recessed block, another setof stand-off insulating rods extending radially from the recesses insaid intermediate sleeve portion, and resilient socket members mountedon the opposite ends of said rods and engaging the inner surfaces ofsaid intermediate and outer sleeve portions respectively, the socketmembers on said first set of rods being disposed medially between therecesses in said intermediate sleeve portion.

3. An ultra-high frequency device having concentric electrodes formingoppositely disposed triodes in reciprocal relation, concentric tubularmetallic members spacing said triodes in longitudinal relation, meansspacing the electrodes and tubular members in coaxial relation withrespect to each other including radially disposed standoff insulatingrods, and metallic socket members secured to one end of each of saidrods and the surfaces of certain of said tubular members, the radialrods between two of said tubular members being staggered with respect tothe rods between the other tubular members.

9. An ultra-high frequency device having concentric electrodes formingoppositely disposed triodes in reciprocal relation, concentric tubularmetallic members spacing said triodes in longitudinal relation, meansspacing the electrodes and tubular members in coaxial relation withrespect to each other including radially disposed standoff insulatingrods, and a pair of metallic disc shields affixed to and extendingoutwardly from the inner concentric tubular member, said shields havingopenings for the passage therethrough of portions of the intermediateelectrodes of said triodes.

10. An electron discharge device comprising a metallic vessel havingopposite ends forming external anode portions, a pair of concentricmetallic members within an intermediate portion of said vessel, acylindrical control electrode supported on each end of one of saidmembers and disposed in spaced relation Within the respective anodeportions, a cylindrical cathode supported on each end of the othermetallic member and concentrically spaced within the respective controlelectrodes, an electrode terminal conductor -ermetically sealed in aWall of said vessel and coupled to said anode portions, a group ofelectrode terminal conductors sealed in said vessel in oppositelydisposed relation to said first conductor, said group of conductorsbeing connected to the cathode and control electrodes through said pairof metallic members, and a protective cap enclos" ing said groupconductors.

11. An electron discharge device comprising a metallic vessel havingopposite ends forming eX- ternal anode portions, a pair of concentricmetallic members within an intermediate portion of said vessel, acylindrical control electrode supported on each end or one of saidmembers and disposed in spaced relation within th respective anodeportions, a cylindrical cathode supported on each end of the othermetallic member and concentrically spaced within the respective controlelectrodes, an electrode terminal conductor hermetically sealed in awall of said Vessel and coupled to said anode portions, a group ofelectrode terminal conductors sealed in said vessel in oppositelydisposed relation to said first conductor, said group of conductorsbeing connected to the cathode and control electrodes through said pairof metallic members, a metallic boss secured to said vessel andsurrounding said group conductors, an insulating cover receptacleenclosing said group conductors and attached to said boss, and terminalson said receptacle connected to said conductors.

12. An electron discharge device comprising a metallic vessel havingopposite ends forming external anode portions, a pair of concentricmetallic members within an intermediate portion of said vessel, acylindrical control electrode supported on each end of one of saidmembers and disposed in spaced relation within it respective anodeportion, a cylindrical cathode supported on each end of the othermetallic member and concentrically spaced within its respective controlelectrode, an electrode terminal conductor hermetically sealed in a wallof said vessel and coupled to said anode portions, a group of electrodeterminal conductors sealed in said vessel in oppositely disposedrelation to said first conductor, said group of conductors beingconnected to the cathode and control electrodes through said pair ofmetallic members, an insulating protective cap enclosing said groupconductors, and a metallic coaxial member surrounding th firstconductor.

13. An electron discharge device comprising a double-ended metallicvessel having opposite end portions forming external anodes of thedevice, a pair of concentric metallic members within an intermediateportion of said vessel, a cylindrical open-Work electrode supported oneach end of one of said members and ext-ending into said anodes, acylindrical cathode supported on each end of the other member anddisposed within its respective open-work electrode, electrod terminalconductors for said members extending through th side wall of saidvessel, radial insulating rods extending between said members and thewall of said vessel, said rods having a metallic coating on the endsthereof, and metallic sockets afiixed to the coated ends of said rodsand carried by said members and vessel wall, respectively,

14. An electronic discharge device comprising a metallic casim includingoppositely disposed hollow anode portions and an intermediatecylindrical wall portion. a metallic column extending axially withinsaid casing for a distance coincident with said cylindrical wallportion, a pair of cathodes mounted on opposite ends of said column anddisposed concentrically within said anode portions, and metallicshielding members carried by said column and extending across gapsbetween said cathodes and anode portions adjacent the juncture of saidanode portions and intermediate wall portion.

15. An electronic discharge device comprising a metallic casingincluding oppositely disposed hollow anode portions and an intermediatecylindrical wall portion, a metallic column extending axially withinsaid casing for a distance coincident with said cylindrical wallportion, a pair of cathodes mounted on opposite ends of said column anddisposed concentrically within said anode portions, another metalliccolumn of a diameter intermediate said first column and said wallportion coaxially mounted therebetween, a

pair of grid electrodes mounted on opposite ends of said latter columnand having parallel wires connected at one end to said latter column andinterposed between the respective cathode and anode surfaces, andmetallic disc shields carried by opposite ends of said first column,said shields having openings therein through which extend said parallelwires of said control electrodes.

15. An electronic discharge device comprising a metallic casingincluding oppositely disposed hollow anode portions and an intermediatecylindrical wall portion, a metallic column extending axially withinsaid casing for a distance coincident With said cylindrical wallportion, a pair of cathodes mounted on opposite ends of said column anddisposed concentrically within said anode portions, another metalliccolumn of a diameter intermediate said first column and said wallportion coaxially mounted therebetween, a pair of grid electrodesmounted on opposite ends of said latter column and having parallel wiresconnected at one end to said latter column and interposed between therespective cathode and anode surfaces, and a pair of metallic discshields having a ring portion embracing opposite ends of said firstcolumn and openings therein through which said parallel wires freelyextend, said disc shields also having inner continuous corrugationsintermediate the ring portion and said openings, discontinuouscorrugations between adjacent openings surrounding said innercorrugations and a reinforced edge, to withstand warping due to thermalenergy stresses prevailing in the discharge path in said device.

17. An ultra-high frequency push-pull oscillation generator devicecomprising a cylindrical metallic enclosing vessel having an externalanode portion on each end thereof, a cylindrical grid-like electrodewithin each anode portion in coaxial relation thereto, a continuousmetallic column having a plurality of spaced apertures and slotsextending longitudinally therebetween and supporting opposite grid-likeelectrodes, a set of radial insulating spacer rods having metalliccoated end portions and stepped intermediate portions extending intransverse directions beween said column and said enclosing vesselintermediate said anode portions, said rods having one end located insaid apertures, a cylindrical box-like cathode in coaxial relationwithin each grid-like electrode, a small diameter metallic couplingcylinder joining opposite cathodes together, a second set of insulatingspacer rods similar to said first-mentioned rods extending radiallybetween said co-lumn and coupling cylinder but in staggered relationwith respect to said first set of rods, a plurality of spring saddleplates secured to the inner surfaces of said enclosing vessel and columnand supporting the metallic coated end portions of said rods extendingtherein, a plurality Of conductors sealed in said vessel and extendingbetween a pair of said first set of rods for connection to said couplingcylinder and said column, a single conductor sealed in said vesselbetween another pair of rods of said first set in opposite relation tosaid plurality of conductors, and an internal loop connection betweensaid. single conductor and said vessel.

18. An ultra-high frequency push-pull oscillation generator devicecomprising a pair of oppositeiy disposed relatively thick wallcylindrical metallic anode portions, the ends thereof b me open and oneof each being" of larger diameter than the other end, said metallicportions forming external anode portions of the device, a medialcylindrical metallic portion secured to the periphery of the smallerdiameter ends of said thick wall portions, dual cylindrical box likecathodes mounted within said anode portions, "1 a1 d-like electrodesmounted between said cathodes and anode portions, said electrodes havingdisc end portions situated in the larger openings in said anodeportions, metallic coupling columns extending between and connected tosaid cathodes and electrodes, respectively, and concentrically mountedwithin medial portion, apertured cove men", ers on opposite ends of saidanode portions and closing the larger diameter openings therein, ametallic plate within each large diameter opening adjacent the disc endportion of said electrodes, adjustable means extending through saidcover members and connected to said plates to vary the capacity relationbetween said plates and discs, anaXial standard extending through saidcathodes and inner coupling column, helical heater elements within saidboxlike cathodes and connected at opposite ends to said standard andinner column, respectively, corrugated metallic diaphragm shields atopposite ends of said inner column and extendin beyond the innerperiphery of said anode portions ut spaced therefrom, said shieldshaving, a plurality of elongated openings in a circular boundary formingpassageways for portions of said id grid-like electrodes, a plurality ofstepped insulating spacer rods having metallic coated ends mounted intransverse radial relation in a medial plane between said columns andmedial metallic portion and resiliently supported at one end on thesurface of one of said coupling columns and said medial portionrespectively, the rods between said coupling columns being orienteddegrees with respect to the rods between one of said columns and saidmedial portion, a group of metallic nipples on the periphery of saidmedial portion, radial conductors extending through said nipples andconnected to said coupling columns and central standard respectively,insulating tubular joints hermetically sealing said conductors to saidnipples, an insulated conductor extending through the opposite side ofsaid medial portion, and a loop member couplin said insulated conductorto said medial portion to serve as an output connection for said anodeportions.

JOHN W. WEST.

REFERENCES CETED The following references are of die of this patent:

UNITED STATES PATENTS record in the 2,251,085 Ul'lk July 29, 194

